Windows Phone 7 - TextBlock Text binding to ViewModel not returning anythinig

问题

I have built a view model and the listbox binds to the ObervableCollection, but a textbox I am using for a temp url wont bind and return data. I am not getting any errors either on compile or run

ViewModel:

public class HomepageModel:INotifyPropertyChanged
{
    public TextBlock bgrImg{get;set;}
    public ObservableCollection<MenuItem> menu {get; private set;}

    public HomepageModel()
    {
        this.menu = new ObservableCollection<MenuItem>();
    }

    public void Load()
    {
        bgrImg = new TextBlock();
        bgrImg.Text = "/Windows7MobileClient;component/Images/Desert.jpg";
        //bgrImg = ;
        menu.Add(new MenuItem("Feed",""));
        menu.Add(new MenuItem("Messages",""));
        menu.Add(new MenuItem("Media",""));
        menu.Add(new MenuItem("Favourites",""));
        menu.Add(new MenuItem("Freinds",""));
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

Homepage.xaml

<controls:PanoramaItem Header="menu">
            <Grid>
                <TextBlock Text="{Binding bgrImg}"/>
                <ListBox x:Name="FirstListBox" Margin="0,0,-12,0" ItemsSource="{Binding menu}" MouseLeftButtonUp="FirstListBox_MouseLeftButtonUp" >
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Margin="0,0,0,17" Width="432">
                                <TextBlock Text="{Binding label}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}"/>
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </controls:PanoramaItem>

I eventual want to use the string for the panorama background image. Sorry if this seems realy obviously simply.

Chris

回答1:

You need to call NotifyPropertyChanged() in your setters for the items you wish to bind to.

回答2:

One more thing I noticed: You are trying to Bind TextBlock to a string Property:

public TextBlock bgrImg{get;set;}
<TextBlock Text="{Binding bgrImg}"/>

Change the type of the property to string:

   public string bgrImg{get;set;}
    <TextBlock Text="{Binding bgrImg}"/>

来源：https://stackoverflow.com/questions/5043873/windows-phone-7-textblock-text-binding-to-viewmodel-not-returning-anythinig

标签

data-binding

windows-phone-7

viewmodel

textblock